1. Technical Field
The present invention relates to a projector that displays an image on a projection plane.
2. Related Art
At the time of displaying a rectangular image (hereinafter, also referred to as an “original image”) on a projection plane such as a screen using a projector, an image (hereinafter, also referred to as a “projection image”) displayed on the projection plane may be distorted into a trapezoid, a parallelogram, and other tetragons due to the relative positional relationship between the projector and the projection plane. Such trapezoidal distortion and projection distortion are called “trapezoidal distortion” in this specification. When trapezoidal distortion is caused in a projection image in this way, a trapezoidal distortion correcting technique of correcting the projection image by projection transform so as to be displayed in a rectangular shape has been used.
JP-A-2002-278507 and JP-A-2003-29714 are examples of the related art.
In a projector that generates an image beam representing an image using a liquid crystal panel, an image (hereinafter, also referred to as “corrected image”) which is obtained by inversely distorting a projection image on a projection plane is generated on the liquid crystal panel. Pixel values of the corrected image are obtained by interpolating the pixels on the basis of the pixel values of an original image. When it is intended to obtain the pixel value of one pixel in the corrected image, for example, the coordinate of the original image corresponding to the pixel in the corrected image is calculated and the pixel interpolation is performed using 16 pixels around the coordinate. That is, the trapezoidal distortion correcting process requires an increase in processing speed to process a large amount of calculation.